An injection device, such as an injection pen, an autopen or an autoinjector, can in principle be suitable for the administration of different drugs, provided the drug has a consistency that allows discharging with the injection device. However, differences result indirectly from the medical indications for which the different drugs are used. Thus, depending on the indication, different requirements are applicable in terms of size, shape, surface and mechanical properties of the housing of the injection device. Thus, in diseases such as multiple sclerosis (MS), for example, the patient's mobility can be impaired, so an injection device that is used for treating patients with MS is associated with special requirements in terms of the shape of the device, to allow the patients to be able to handle the injection device at all. Thus, in the case of medical indications that relate to the handling of injection devices by children or persons of small stature, it can be necessary to design the injection devices to be as slender and small as possible.
Here, the term “drug” comprises any flowable medical formulation that is suitable for the controlled administration through a means such as, for example, a cannula or hollow needle, comprising, for example, a liquid, a solution, a gel or a fine suspension containing one or more medical active substances. “Drug” can refer to a composition with a single active substance or to a premixed or co-formulated composition with a plurality of active substances from a single container. The term drug comprises medicines such as peptides (for example, insulins, insulin-containing drugs, GLP-1-containing preparations as well as derived or analogous preparations), proteins and hormones, biologically prepared or active substances, active substances based on hormones or genes, nutrition formulations, enzymes and other substances either in solid (suspended) or liquid form, but also as polysaccharides, vaccines, DNA or RNA, or as oligonucleotides, antibodies or parts of antibodies as well as suitable base substances, adjuvants and carrier substances.
An injection device is known from U.S. Pat. No. 8,535,274, in which a U-shaped shell can be snapped on in the area of the handle. This shell can be used for ergonomic as well as for decorative purposes and it can be replaced easily by the user. The U shape of the shell implies that the injection device cannot be enclosed completely by the sleeve, which limits the three-dimensional shaping.
A syringe with an additional housing sleeve is known from US2009/0157012, which is mounted in a slidable manner on the syringe. The sleeve, which can be manually shifted in the axial direction by the user, ensures visibility of the needle for protection before and after an injection. The sleeve can be detachably locked in several positions on the syringe. The sleeve can also be pulled off the syringe by the user.
An injection device is known from WO03/105927, in which a portion of the housing external surface can be provided with a surface-finish coating. This coating can be of purely decorative nature or it can have a function. In this invention, it is disadvantageous that the three-dimensional shape of the injection device can only be influenced to a minute extent.
An injection device is known from WO2011/124633, which can be supplemented on its lateral area with differentiation shells 204 and 206. These shells can be assembled by the trained user on the injection device and also removed again. Here, the differentiation shells 204 and 206 comprise snap connection elements designed to be complementary to one another, that is to say the differentiation shells 204 and 206 are not attached to the housing itself, instead the shells secure one another. Furthermore, the injection device is designed in such a manner that it can only be used if the differentiation shells 204 and 206 are mounted. The differentiation shells 204 and 206 thus influence the functionality of the injection device.
For manufacturers of injection devices, drug manufacturers, health insurers and persons to be treated, there is a need to have injection devices available that are as advantageous as possible while being reliable and effective. Accordingly, it would be desirable to have an injection device that has an invariable, proven, reliable and predetermined technical design with an invariable housing, wherein, via additional add-on parts, which are firmly and non-detachably connected to the housing, the shape, the haptics, the surface topography and the ergonomics of the injection device can still be adjusted during the production of the device, thus taking into account the requirements of the medical indications in a simple and advantageous manner.